The Vitamin A xylolipid purified from the lipid extract of rat liver will be further characterized with regard to the mode of linkage of the retinoid and the pentose through phosphoester bonds. The glycolipid will be hydrolyzed, the lipid catalytically reduced to the stable perhydroretinoid and the mass spectra fragmentation pattern studied. The purified retinoxylo lipid will be tested as a xydosyl donor in enzymic reactions to endogenous glycoprotein acceptor and whether an exogenous xylose acceptor like the Smith-degraded chondroitin sulfate would act as a stimulator in this reaction. Xylose is O-glycosidically linked to protein and is the connecting link in mucopolysaccharides. Our studies show that the alkali stable xylose, present in mammalian glycoprotein is in a different kind of linkage and position. We plan to study the carbohydrate side chains of the glycoprotein and the probable significance of the presence of this unique xylose residue. The enzymatically formed zylo lipid will be compared with the glycolipid isolated from the in vivo experiments. Similar studies will be carried out with other sugars and sugar nucleotides like mannose, N-acetyl glucosamine, GDP-mannose and UDP-N-acetyl glucosamine.